The following will help to check if you know all the needed techniques:

6 not in r8c1, it is in r7c2 or r8c2 (Column on 3x3 Block interaction)
1 not in r5c5, it is in r5c4 or r6c4 (Column on 3x3 Block interaction)
1 not in r6c5, it is in r5c4 or r6c4 (Column on 3x3 Block interaction)
8 not in r4c9, it is in r4c7 or r6c7 (Column on 3x3 Block interaction)
8 not in r5c9, it is in r4c7 or r6c7 (Column on 3x3 Block interaction)
8 not in r4c6, it is in r5c4 or r5c5 or r5c6 (Row on 3x3 Block interaction)
8 not in r6c4, it is in r5c4 or r5c5 or r5c6 (Row on 3x3 Block interaction)
8 not in r6c5, it is in r5c4 or r5c5 or r5c6 (Row on 3x3 Block interaction)
8 not in r6c6, it is in r5c4 or r5c5 or r5c6 (Row on 3x3 Block interaction)
3 not in r1c5, it is in r1c1 or r1c2 of the 3x3 (3x3 Block on Row/Column interaction)
3 not in r1c6, it is in r1c1 or r1c2 of the 3x3 (3x3 Block on Row/Column interaction)
3 not in r1c9, it is in r1c1 or r1c2 of the 3x3 (3x3 Block on Row/Column interaction)
2 not in r7c9, Hidden Pair 1 9 in r7c7 and r7c9 (in Row)
3 not in r7c7, Hidden Pair 1 9 in r7c7 and r7c9 (in Row)
3 not in r7c9, Hidden Pair 1 9 in r7c7 and r7c9 (in Row)
5 not in r7c7, Hidden Pair 1 9 in r7c7 and r7c9 (in Row)
5 not in r7c9, Hidden Pair 1 9 in r7c7 and r7c9 (in Row)
6 not in r7c9, Hidden Pair 1 9 in r7c7 and r7c9 (in Row)
7 not in r7c7, Hidden Pair 1 9 in r7c7 and r7c9 (in Row)
2 in r7c3 - Unique Horizontal